Archive for the 'Bird Behavior' Category

Feb 25 2014

Bluebird Fight

Eastern bluebird fight (photo by Karen DeSantis)

We think of eastern bluebirds as gentle birds.  They seem to be poor fighters and often lose battles with house sparrows and starlings, so I was surprised to learn from Karen DeSantis that she witnessed two male eastern bluebirds in a long ferocious fight in late February a few years ago.

Karen described on PABIRDS how the fight began with chasing, then escalated into periodic knock downs and grim combat on the ground.  The males fluttered and rolled over a distance of about 30 feet while the female followed every move, twittering as she watched.  The birds were so oblivious that Karen was able to take photographs of the 15-minute battle.  Karen wrote, “It was the long duration of the fight that interested me the most.”

Though we might not realize it, these battles are consistent with bluebird behavior.

During the winter bluebirds flock in family groups and huddle together to stay warm.  In early spring their togetherness ends as the fathers eject their sons from the group before ‘Mom’ and ‘Dad’ nest again.

But the battle Karen witnessed was not a mild family squabble.  Its intensity indicates the guys were fighting over the lady.

Bluebirds are usually monogamous but about 20% of the young come from extra-pair copulations.  The males seem to know if their ladies’ eyes are wandering and guard their mates more closely if they’ve been messing around.  According to Birds of North America Online, “Experimental evaluations (Gowaty 1980) indicate male-male aggression most likely serves to protect threatened paternity. Males are aggressive to males usually in defense of paternity.”   These battles can be so intense that they end in the crippling or death of one of the birds.

Bluebirds may seem gentle but don’t mess with their mates!  Click on Karen’s photo above to watch a slideshow of the fight.

 

(photos by Karen DeSantis)

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Feb 05 2014

Prefers To Raise An Only Child

Scarlet macaw (photo from Wikimedia Commons)

Last fall Parrot Confidential introduced us to the ARA scarlet macaw recovery project in Costa Rica and a bird named Geoffrey who was abandoned by his mother.  I assumed at the time that Geoffrey was rescued because his mother was new to motherhood and unskilled in raising her first brood.

But no.  Scarlet macaws have a very unusual parenting strategy.  The female lays up to four eggs but when the eggs hatch the parents choose just one of the nestlings — usually the first — and shower it with attention.  The rest are ignored, unfed, not brooded.  They die within three weeks.  The parents raise an only child.

I learned about this very unusual behavior in an article in wired.com about the Tambopata Macaw Project in southeastern Peru.  Since 1989 the project has collected a wealth of information on scarlet macaw biology and behavior including the birds’ habit of raising only one chick each year.  From Nadia Drake’s article:

Observations suggest that this outcome is one of choice, rather than resource limitation. So far, the reasons why are still a mystery. This parenting strategy seems to be unusual even among birds, which often lay extra eggs and then distribute limited resources among chicks with brutal efficiency.

The truth is that macaw chick mortality does not appear to be the accidental or inevitable result of scarce resources.
“This is death by neglect,” said ornithologist Donald Brightsmith of Texas A&M University. “Complete and utter neglect.”

This parenting strategy is an unfortunate trait for an endangered bird but it explains why the ARA Project has a natural supply of baby scarlet macaws:  Every nest has an abandoned nestling.  By raising the “extra” birds the project boosts the local population.

Scarlet macaws are very intelligent.  They have a reason for choosing to raise an only child.  We just don’t know what it is yet.

Read more here at wired.com.

 

(photo in the public domain from Wikimedia Commons. Click on the image to see the original)

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Jan 26 2014

Bird On Camera

Pygmy nuthatch on camera (photo by Ed Sweeny (Navicore) via Wikimedia Commons)

Birds are often on camera, but rarely on the camera.

This photo of a pygmy nuthatch was an experiment by Ed Sweeney (Navicore on Flickr).  Thanks to its Creative Commons license on Wikimedia Commons, I found the photo and learned of Ed Sweeney’s extraordinary photographs.  See more on his Flickr page here.

 

(photo by Ed Sweeney, on Wikimedia Commons.  Click on the image to see the original and Creative Commons license.)

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Jan 25 2014

This Is Getting Old

Published by under Bird Behavior

White-throated sparrow in cold and snow (photo by Steve Gosser)

Unseasonably cold weather continues in Pittsburgh though we’ll have a “heat wave” of 26oF today while it’s snowing 2-4 inches.  Then the temperature will dip to -7oF by Monday night.  Erf!

When Steve Gosser posted this white-throated sparrow on Facebook, many remarked that the bird is fluffed up and frowning!  It looks like he’s tired of winter.

I agree.

“This is getting old.”

(photo by Steve Gosser)

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Jan 24 2014

Flight Paths

Published by under Bird Behavior

 Starling flight-path video by Dennis Hlynsky on Vimeo

If birds left a visual trail in the sky, what would their flight paths look like?

Dennis Hlynsky, an artist and professor at the Rhode Island School of Design, has been experimenting with this for several years.  He became interested in birds when “During the winter of 2008 I left the house in the wee early morning looking for anything to record with my new pocket video camera. I began to notice life above.”  Since then he’s been filming birds and animals, then using Adobe After Effects to convert their motion to dotted trails.  Fast-moving birds become open dashes, slow-moving ones are thick lines.

Starling videos are especially interesting because the flocks collect a few birds at a time and flee in a tightly packed blob.  Click on the screenshot above to watch Hlynsky’s video “data in data out” of starlings on wires in East Providence.

Thanks to Traci Darin for pointing out this video in an article on the Colossal website where you can see an animation and three additional flight path videos.  Or click here for Dennis Hlynsky’s “small brains on mass” website where he’s posted videos of birds, water striders and the carp feeding at Linesville, PA.

(screenshot from Dennis Hlynsky’s video “data in data out” on Vimeo)

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Jan 23 2014

Gregarious

House sparrows in snow in Moscow (photo from Wikimedia Commons)

House sparrows are always gregarious, but more so in winter when they flock together in large numbers.

In the morning and afternoon they disperse to feed, but twice a day — at midday and in the evening — they gather in dense shrubs or evergreens and chatter for an hour or more.  They sound a lot like this.(*)

You might not hear them in today’s cold weather but when you do it’s unmistakable.  They’re in a bush alive with birds … but you can’t see them.  I’ve tried to count them but they fall silent and hide when I approach.  I rarely see even one.

Here’s a flock in a tree, somewhat hidden but easier to see than inside a privet hedge!

House sparrows in a bush in Saskatoon (photo from Wikimedia Commons)

House sparrows love each others’ company so much that, according to the Stokes Guide to Bird Behavior, some travel up to four miles to join the roost.

“Gregarious” works for house sparrows — from Latin gregarius (from grexgreg- ‘a flock’) + -ous (to make it an adjective).

 

(photos from Wikimedia Commons. Click on the images to see the originals)

(*)  The sounds at the link above are similar but not quite the same as winter chatter because they’re from a more intense breeding chase in April.  Listen to this segment from BirdNote for all the sounds house sparrows make.

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Jan 08 2014

Staying Warm, Continued

Inca doves in a huddle (photo by Penny Meyer via Flickr, Creative Commons License)

In this week’s very cold weather it’s hard to stay warm but birds have a few strategies that help.

They eat a lot and they also naturally shiver to stay warm.  Shivering sounds pathetic but it actually works because the muscles generate heat.  The big pectoral (breast) muscles are the best for this.

Some birds shelter in nooks or crannies of hollow trees or on the outsides of our buildings.  Look at chimney tops and you’ll see starlings absorbing the warm exhaust.  On Monday I saw a peregrine at Pitt facing inward at a high window on the Cathedral of Learning.  The window was warmer than the surrounding air.

Other birds come indoors. On Monday afternoon Richard Nugent reported he’d found a Carolina wren sheltering in his heated garage as the temperature was heading for -12 degrees that night.  What a smart wren!  Richard put out food and water for the bird to enjoy while it waited for the weather to improve.

Huddling helps. Inca doves not only huddle sideways as shown above but they make pyramids two or three rows high.  According to Ornithology, as many as 12 Inca doves will form a pyramid, fluff their feathers and face downwind in a sheltered sunny place.  “In large pyramids, doves exposed on outside positions try for better positions in the top row and cause the whole pyramid to readjust.” This sounds like a circus act, amazing to watch.

Last night was the last of the bitter cold.  If the birds can make it through today the weather will moderate, then switch to above-normal temperatures this weekend.

Hang in there, little birds.  Help is coming soon!

 

(photo by Penny Meyer via Flickr, Creative Commons license. Today’s Tenth Page is inspired by page 158 of Ornithology by Frank B. Gill.)

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Dec 29 2013

Take Me To The River

Peregrine bathing in the Monongahela River (photo by Michelle Kienholz)

Yesterday, while the Christmas Bird Counters were absent from Duck Hollow, Michelle Kienholz stopped by to take a run on the Duck Hollow Trail.  Surprise!  From the parking lot she saw a peregrine falcon taking a bath in the Monongahela River.  Very cool!

A long time passed — at least 10 minutes — and the peregrine continued to stand in the water.  Michelle noticed a fisherman in waders standing further out than the peregrine but the falcon didn’t leave.  Why was it staying there so long?  Was something wrong?  She emailed me with a snapshot.

Peregrine bathing in the Mon River, 28 Dec 2013 (photo by Michelle Kienholz)

Peregrine bathing in the Mon River, 28 Dec 2013 (photo by Michelle Kienholz)

I was at home logging the 6,000 crows I counted over my house at dawn when I received her message so I drove down to Duck Hollow to take a look.  No peregrine in sight but there was a merlin in the river near the fisherman!

The fisherman left the water, the merlin flew to a dead snag overlooking the river, and my phone beeped with another message from Michelle saying the peregrine had flown upriver after 20 minutes in the water.

I looked at the snag again.  The merlin was gone, a kestrel was standing in its place, and the merlin was in the river taking a bath.  Michelle came back from the trail and I showed her the other two birds.

Here’s the merlin bathing. Quite a different bird!

Merlin bathing in the Mon River, 28 Dec 2013 (photo by Michelle Kienholz)

And then the merlin left…

Wet merlin leaving the river, 28 Dec 2013 (photo by Michelle Kienholz)

 

I wish I’d been there earlier.  In Pittsburgh there are only three possible falcons — American kestrel, merlin and peregrine falcon — and Michelle saw all three within half an hour.  A Falcon Sweep!   Her sightings were added to the Pittsburgh Christmas Bird Count.

 

p.s. One of Michelle’s photos showed the peregrines’ bands. The USFW band is pinkish and shows ‘160’ or ‘760’ (right leg, left side of photo). The color band (left leg, right side of photo) is black/green and the black seems to end in ‘5’. Who might this be?

Peregrine bathing in the Mon River at Duck Hollow (photo by Michelle Kienholz)

Dorothy, the matriarch at the University of Pittsburgh nest, has a pinkish USFW band with the number 1807-77607. Her black/green band is 5/*A.   Hmmmmm!

(photos by Michelle Kienholz)

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Dec 13 2013

Success Through Nepotism

Siberian Jay (photo from Wikimedia Commons)

The practice of giving plum jobs to your relatives is widely frowned upon but nepotism is a very successful survival strategy — so successful that some birds use it too.

Closely related to North America’s gray jay, Siberian jays (Perisoreus infaustus) live in the boreal forest of Northern Europe.  Like other corvids in limited habitats they breed cooperatively.   Each breeding pair has a suite of relatives who help guard the nest and feed the young.  Often the kids stay with their parents even though they’re old enough to breed.

Studies in Sweden have shown that male Siberian jays who stay with their parents are much more successful than those who leave home because their fathers practice nepotism.  The father jays protect their own sons and harass incoming males who try to join the group.  The sons thrive and learn while they wait for a good territory to become available.

The exception proved the rule.  Ekman and Griesser experimentally removed fathers and watched as they were replaced by despotic immigrant males who ejected the missing fathers’ sons.  If dad’s not there to protect you, watch out!

Success through nepotism.

 

(photo of a banded Siberian jay from Wikimedia Commons. Click on the image to see the original.
Today’s Tenth Page is inspired by page 390 of Ornithology by Frank B. Gill.
)

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Nov 28 2013

Band Of Brothers

Two male wild turkeys chase a police car in Moorhead, MN (photo from Wikimedia Commons)

Chances are these turkeys are brothers, working together to chase the police out of their territory.

Wild turkeys are very social birds whose flocks are often composed of siblings.  This habit starts young when they’re all poults together and continues as adults.

Each sex within the flock develops a pecking order.  Literally.  Who has the right to peck someone else?  The ladies figure out the hierarchy and tend to leave it at that without a lot of jostling.  The guys, on the other hand, are always stirring things up.  Which of them is most dominant?  They fight about it.  In this case they’re fighting a police car.

Turkeys are brothers in love and war.  Groups of male turkeys strutting and displaying together are usually brothers, collaborating to attract the opposite sex.  One of them is dominant and he’ll get to mate with the ladies.  His brothers display but they don’t become fathers.

But don’t feel sorry for the lesser guys. Soon enough they’ll fight about it and a different male may achieve dominance in the band of brothers.

 

(photo from Wikimedia Commons of two male wild turkeys chasing a police car in Moorhead, Minnesota on April 29, 2013. Click on the image to see the original.  Today’s Tenth Page is inspired by page 338 of Ornithology by Frank B. Gill.)

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